Means to protect submarine-mine fields



F. I. DU PONT.

MEANS TO P T CT SUBMARINE MINE FIELDS, APPL} ION FILED APR.4.19XI.

147' 7 ORA E Y.

Pater Y Ma 191i).

FRANCIS I. DU FONT, 0F WILMINGTON, DELAWARE.

MEANS TO PROTECT SUBMARINE-MINE FIELDS.

Specification of Letters Patent.

Patented May 27, 1919.

Application filed April 4, 1917. Serial No. 159,647.

To all whom it may concem:

Be it known that I, FRANCIS I. DU PONT, a citizen of the United States,residing at Wilmington, county of New Castle, and State of Delaware,have invented a new and useful Improvement in Means to ProtectSubmarine-Mine Fields, of which the following is a full, clear, andexact description, reference being had to the accompanying drawings,which form a part of this specification.

My invention relates to the subject of naval defense and has especiallyfor its object the safeguarding of certain water fronts and marinehighways in case of war. In such waters, mines and floating bombs areanchored at various points. These mines, though entirely invisible fromthe surface, are not submerged very deeply so as not to be beyond thedepth of the smaller craft of the enemy.

It is well understood in general how these mines are constructed andplanted. An effective means used by an enemy to clear a safe passageoversuch amine protected area is to run over it two light draft vessels,in

parallel lines, trailing a cable between them. The cable is allowed tosink deep enough to sweep against the anchor lines of the mines in itspath, and in this way the mines are dragged away from their anchorages.A mine field may be thus partly or wholly destroyed The objefit of myinvention is to provide means for nullifying this/action of the enemyand protecting the mines. My invention consists of cable-severingmechanism attached to the mine anchor line below the mine, or preferablyto a separately anchored line contiguous to the mine, in such mannerthat the dragging cable of the minedestroyers will engage said cuttingmechanism and be severed thereby before it has a chance to work anysubstantial damage to the mine field.

Embodiments of the invention are shown in the accompanying drawings, inwhich Figure 1 is a view, partlyin elevation and partly in verticalsection, of the shearing mechanism and the submerged anchored carriertherefor. Fig. 2 is a section on the line 22 of 1. Fig. 3 is anelevation of a modification. Fig. 4 is an enlarged vertical sectionalong the shears of Fig. 3. Fig. 5 is an enlarged cross section on theline 5-5 of Fig. 4.

the'mine field, and anchored in position by means of a cable I)connected with an anchor or weight (not shown) at the bottom of the bodyof water.

Secured in one side of the body a is one aw or blade 0 of a pair ofshears. This jaw is preferably fixed and extends vertically. The otherjaw d is pivoted, at its upper end, to the body a. This jaw also extendsdownward but diverges somewhat from the fixed jaw. The space between thecutting edges of the jaws is open at the bottom and closed at the top.

The pivoted jarw d has an inwardly disposed arm 6 which engages a pistonor plunger f in a piston chamber g, the space beneath the piston actingas a container for explosive material. A spring-actuated firing pin 12,is restrained from operation by means of its engagement with one arm ofa bell-crank lever z pivoted in a recess in the body a. The other arm ofthe bell-crank extends into the space between, or in line with the spacebetween, the cutting jaws. To exclude the entrance of moisture to thepowder charge, and also to protect the jaws of the shears fromcorrosion, a very thin copper sheathing j (indicated in dotted lines inFig. 1) incloses the/movable jaw, covers the projecting edge of thefixed jaw and incloses the space at the root of the jaws communicatingwith the explosive charge and its firing mechanism. This coppersheathing is readily severed when the jaws of the cutter close, buttends to hold them in open position until they are positively actuated.

The upper part of the body a is bulbous shaped, affording snflicient airspace to float the mechanism, while the lower part is tapered downward,presenting an upwardly and outwardly extending inclined surface leasesthe firing pin it, which i nites the powder charge. The explosion orcesthe plunger f against the arm 6, thereby swinging the jaw d toward thejaw c and severing the dra ging cable.

In the embodiment of the invention shown in Figs. 3, 4 and 5, thedragging cable itself supplies the force required to operate the shears.The latter consist of two shearing jaws or blades m and n, one carriedby the body 0 and the other by a holder p secured at its upper end tothe body 0 and thence extending down alongside of, but divergingsomewhat outwardly from, the wall of the body 0. Preferably both jawsare movable, and preferably, also, both jaws are arranged to slideupwardly, thus causing opposing points on the two jaws to approach eachother. The sliding movement of the jaws is facilitated by caus ing theinner longitudinal edges of the jaws to travel in elongated recesses incontact with rollers 1' rotatable on the bottoms of a the recesses.

It is obvious that if a dragging cable, by its contact with theanchorage cable, is guided into-the space between any two jaws m and n,it will, by virtue of its own pulling force, draw the jaws upwardly andthgi'efore cause them to sever the dragging ca e. P

A plurality of shears m, n, are provided about the periphery of the body0, as in the case of the pivoted shears before described, and alsosimilar to that case shears m, n, are entirely covered and protected bythin copper shell 'iindicated at s to preclude corrosion. '1

Having now fullv described my invntion, what I desire to claim andprotect by Letters Patent is v 1. Means to protect submarine mine fieldscomprising a submersible body, an anchorage cable to which the body issecured, and

cutting means positioned and adapted to sever any dragging'cable thatengages the anchorage cable and is guided thereby relatively upwardtoward the cutting means.

2. Means to protect submarine mine fields comprising a body adapted forsubmergence beneath the surface of the water, an anchorage cable towhich the body is secured, and

shears the jaws of whichv open downward in posltlon to engage anydragging cable that engages the anchorage cable and is guided therebyinto the space between the jaws.

3. Means to protect submarine mine fields comprisinga body adapted forsubmergence beneath the surface of the water, an anchorage cable securedto the body, shears carried by the body the jaws of which open downwardtoward the anchorage cable whereby the dragging cable is guided upwardbetween the jaws, and means controlled by the dragging cable to effect arelative approach of the jaws to sever the drivln cable.

4. Means to protect submarine mine fields comprisingabody adapted forsubmergence beneath the surface of the water, an anchorage cable securedto the body, shears carried by the body the jaws of which open downwardtoward the anchorage cable whereby the dragging cable is guided upwardbetween the jaws, a container for an explosive charge, means operable bythe dragging cable to means operable by the explosive charge to cause arelative approach of the jaws of the shears to sever the dragging cable.

5. Means to protect submarine mine fields comprising a body adapted forsubmergence beneath the surface of the water, shears, and a relativelythin and readily severable protective sheathing for the shears.

6. Means to protect submarine mine fields comprising a body adapted forsubmergence beneath the surface of the water, and a plurality of shearseach of which is adapted to sever a-dragging cable, said shears beingarranged along the outside of said body on different radii of the bodysvertical axis.

7. Means to protect submarine mine fields comprising a submersible bodyhaving a cone-shaped lower end. and a pair of shearing jaws one of whichsubstantially alines with the "tapered side of the lower end of thebody, while the other of which extends downward alongside the body andspaced from the other jaw, whereby a dragging explode the charge, and.

cable contacting with the lower end of the

